A known seat sliding apparatus for a vehicle is disclosed in JPH09-118155A. According to the disclosure in JPH09-118155A, the known seat sliding apparatus includes a pair of lower rails provided at the right and left of the seat sliding apparatus, respectively, and fixed to a vehicle floor, and a pair of upper rails slidably supported by the lower rails, respectively, and supporting a vehicle seat. Each of the lower rails retains a screw shaft which extends in a front-rear direction of the vehicle so that the screw shaft is rotatable. Each of the upper rails fixedly retains a nut member which is threaded onto the screw shaft. A slide drive portion, which includes a driving motor and a transmission mechanism for rotating the screw shaft, is provided at the lower rails. The driving motor and the transmission mechanism are fixed to an inner surface of a bottom wall of a front frame which is fixed on between the lower rails and which is formed in a U-shape in cross-section. The driving motor and the transmission mechanism cooperate to actuate each of the screws which are individually retained by the respective lower rails. Upon the actuation of the screw shaft by the slide drive portion to rotate, the nut member is relatively displaced in an axial direction, and thus the upper rail slides in a front-rear direction of the vehicle relative to the lower rail. By means of this sliding movement of the upper rails, the position of the vehicle seat which is supported by the upper rails is adjusted in the front-rear direction of the vehicle.
Generally, the vehicle seat is configured to be adjustable not only in a front-rear direction but also in an upward and downward direction. In those circumstances, one of a screw shaft and a nut member is rotatably supported by each of upper rails provided laterally spaced from each other at the right and left sides as a pair, the nut member or the screw shaft which is engaged with the screw shaft or the nut member rotatably supported by each of the upper rails is supported by a lower rail so as not to rotate, and the screw shafts or the nut members rotatably supported by the respective upper rails are driven by a slide drive portion, which includes a drive motor and a transmission mechanism and is fixed between the upper rails, to rotate.
Further, a level of a stroke for a height adjustment of a mechanism for lifting or lowering a seat tends to increase. In a case where the vehicle seat is adjusted to be in a higher position, the slide drive portion provided under the seat is likely to be seen from a front. This necessitates considering ameliorating an appearance of the slide drive portion. Further, because it is possible that an occupant reaches the slide drive portion when he/she gropes under the seat, it is likable to consider the safety of the occupant when using the seat apparatus. As counter measurements for the foregoing drawbacks, an edge portion of an end surface of a long bracket to which parts of the slide drive portion are assembled is bent upward or a bent portion is additionally provided to the end surface in known constructions. However, the known counter measurements are not sufficient and rather increases a manufacturing cost and causes another drawback regarding restrictions for formability of the bracket.
Further, a wire for supplying electric power to the driving motor of the slide drive portion is arranged through and/or under the seat. And according to known structures, a separate bracket particularly for retaining a wire harness and a connector, or the like, is provided in the vicinity of a sliding apparatus. However, according to the above-explained known structures, a structure provided under the seat is complicated and a manufacturing cost is increased because of an increase of the number of parts and an increase in assembling time, thus an improvement in this regard is desired.
A need thus exists for a seat sliding apparatus for a vehicle which is not susceptible to the drawback mentioned above.